Sunday's new Supergirl ended on a kryptonite cliffhanger -- and things are only going to get more dire from here.

"I think it'll take the whole team to try and save her," executive producer Robert Rovner said of the episode's scary final shot, which shows Supergirl (Melissa Benoist) plummeting to Earth after being targeted by the diabolical brother-sister duo of Mercy and Owen Graves (Rhona Mitra and Robert Baker), who escaped from D.E.O. custody with the help of a turncoat agent.

"Then once they do, [they will be] kind of rallying to figure out how to stop what is now gaining much greater momentum, this kind of fear of aliens. So it kind of sets the stage for everything that comes this season."

As for how D.E.O. Director Alex Danvers (Chyler Leigh) will handle the attack on her superhero sister by one of her own, Rovner noted, "I think it feels more personal, because they're using our agents against us."

"They fight back as they always fight back," he added. "But I think it stings a little bit more, especially for Alex moving forward, because somebody that she trusted has betrayed her in a much deeper way, and so she wants to fix that."

On Alex's side at the D.E.O. is her super-smart right-hand man, Braniac 5, aka "Brainy" (Jesse Rath). "They're starting to find a rhythm together," Rath said of Brainy and Alex's dynamic. "I think it's kind of like a big sister-type relationship that they have. I think he really respects her."

"I love shooting with Chyler," he raved. "It's been a lot of fun, especially in these first four episodes which we shot all out of order. It was great... She's a very hard worker and just the way she carries herself. And then she's also like, a mother of three, she's just doing everything. So I was very impressed by her. And I learned a lot from her."

However, the pair may have an uphill battle to fight together in the coming episodes. The anti-alien discontent in the D.E.O., and throughout the country, runs deep, as evidenced by the rabid group of supporters that gather for a rally held by one of the season's big bads, Agent Liberty (Sam Witwer), a disenfranchised citizen turned masked agent of chaos. Hatred and mistrust of the alien population even permeates everyday life, as Brainy discovers during a trip to his local pizza place.

"I think this episode was him learning that there's a difference between just knowing how things are going to end up, versus experiencing them firsthand," Rath noted, explaining that while Brainy and his fellow Legionnaires obviously know the way the world turns out, they may not have all the information about the past. And, as Alex notes, the future is subject to change. "[He's] learning firsthand the seriousness of the situation that they're in, and realizing that maybe the past isn't as safe as he thought it was."

However, on Sunday's episode, the 31st century native met a fellow friend from the future -- though he may not know it just yet. When his true alien form is revealed to the prejudiced pizza shop owner, Brainy is taken aback by his violent reaction, having considered him a friendly acquaintance. But someone else is there to put the man in his place: the newest CatCo reporter, Nia Nal (Nicole Maines).

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"It's a very harsh reality, because you thought you had a relationship with somebody until they find out you're not exactly what they think you are," Rovner said of the confrontation. "And so it becomes I think maybe more painful for Brainiac, because he's not expecting it."

Nia defends Brainy, and the pair have a nice moment of connection. "I think that he knows a little bit about what it's like to be picked on for something that's kind of out of his control," Rath noted. Later, her impassioned conversation with CatCo boss James Olsen (Mehcad Brooks) -- and her decision come out to him and speak from her experiences as a transgender woman -- inspires him to pen and publish a controversial editorial on justice and equality.

"I've been having a lot of fun shooting with Nicole, she's great," Rath raved. "She's super funny. And I think she is someone who's grown up really fast in her life, and that's given her this real-life superhuman ability to learn at super speed. She's like the real-life Flash."

The actor also noted that the pair continue to have "cool" scenes together in future episodes."We're all just very impressed by her talent and her personality. So we have a lot of fun shooting those scenes."

Rovner also confirmed that the pair, who have romantic history in the DC Comics canon, will continue to "cross paths as the season continues."

"I feel for Nicole because flirting with Brainy is like, a really hard thing," Rath joked of his on-screen persona. "I give her nothing. And she's got to do all the heavy lifting."

According to Rovner, the pair have more in common that it would first appear. "What's great about Brainy, I think, is that because he's from the future and does know Dream Girl in the future, he can help her on her path to become a hero."

Though we don't yet know how much Brainy has put together about Nia's true heroic identity, fans get a quick tease of her dream powers this week, when James catches her napping at her desk.

"That's a nod off to that," Rovner laughed, noting that there is more of an origin story to come for Nia and Dreamer. "But yes, it gets teased in the earlier episodes, and then it becomes a much bigger thing."

"I think she, like all of our characters, is trying to navigate the world and kind of find a path for themselves," he added. "She has a great relationship with the rest of the [characters], both as she's kind of searching for how to be a great reporter, and love, and everything that everybody deals with, in addition to dealing with the fact that she has a special ability."

Maines spoke to ET's Philiana Ng last week about joining the Supergirl cast, noting how excited she was to increase the visibility of trans performers and characters on TV.

“What’s important about having a trans character in shows like these is that we’re able to look at issues of goodness, justice and crime-fighting through a trans lens, which she also does with her being a woman and a reporter and a superhero," she explained. "She’s able to bring a unique perspective to all of these issues."